placing the telephone in a position neutral to one of the spirals, then
only the sound proceeding from the other can be heard. These results
occur in whatever position the spirals are placed relatively to each
other, thus proving that there is no interference with or blending of
the separate lines of force. The whole arrangement will be left in
working order at the close of the meeting for any gentlemen present to
verify my statements or to make what experiments they please.

In conclusion, I would ask, what can we as practical men gather from
these experiments? A great deal has been written and said as to the best
means to secure conductors carrying currents of very low tension,
such as telephone circuits, from being influenced by induction from
conductors in their immediate vicinity employed in carrying currents of
comparatively very high tension, such as the ordinary telegraph wires.
Covering the insulated wires with one or other of the various metals has
not only been suggested but said to have been actually employed with
marked success. Now, it will found that a thin sheet of any known metal
will in no appreciable way interrupt the inductive lines of force
passing between two flat spirals; that being so, it is difficult to
understand how inductive effects are influenced by a metal covering as
described.

Telegraph engineers and electricians have done much toward accomplishing
the successful working of our present railway system, but still there
is much scope for improvements in the signaling arrangements. In foggy
weather the system now adopted is comparatively useless, and resource
has to be had at such times to the dangerous and somewhat clumsy method
of signaling by means of detonating charges placed upon the rails.
Now, it has occurred to me that volta induction might be employed with
advantage in various ways for signaling purposes. For example, one or